Trends in survival of leukemia among children, adolescents, and young adults: A population-based study in Osaka, Japan

Prevalence of survivors of childhood cancer based on a population-based cancer registry in Osaka, Japan

Although the survival rate of patients with childhood cancer has greatly improved, long-term survivors face specific problems such as the late effects of cancer treatment. In this study, we estimated the number of people who had experienced childhood cancer to predict their needs for medical care and social resources. Using data from the population-based Osaka Cancer Registry, we identified children aged 0-14 years who were diagnosed with cancer between 1975 and 2019. We estimated the prevalence on December 31, 2019, and the 5- and 10-year prevalence (i.e., the number of survivors living up to 5 or 10 years after the diagnosis of cancer) over time. The prevalence proportion was age-standardized using a direct standardization method. The prevalence estimates for Osaka were applied to the national population to determine the national prevalence in Japan. Among 8186 patients diagnosed with childhood cancer in Osaka, 5252 (987 per million) survived until December 31, 2019. The 5-year prevalence per million increased from 194 in 1979 to 417 in 2019 (+116%), while the 10-year prevalence increased from 391 in 1984 to 715 in 2019 (+83%). Based on the long-term registry data, an estimated 73,182 childhood cancer survivors were living in Japan by the end of 2019. The increasing 5-year and 10-year prevalence proportions indicate the continued need for cancer survivorship support for children, adolescents, and young adults. These estimates of the prevalence of childhood cancer survivors, including long-term survivors, may be useful for policymakers and clinicians to plan and evaluate survivorship care.

Impact of aging on acute myeloid leukemia epidemiology and survival outcomes: A real-world, population-based longitudinal cohort study

Acute myeloid leukemia (AML) is a severe and fatal form of leukemia that is prevalent in the older population. In this longitudinal retrospective study, we investigated the epidemiology and survival rates of patients diagnosed with de novo acute myeloid leukemia in South Korea from Jan 1, 2011, to Aug 31, 2020. We used real-world data from the Health Insurance Review and Assessment Service database. We observed an increase in the number of acute myeloid leukemia cases, with age-specific incidence rates escalating in older patients. In contrast a long-term decrease from 1.94 to 1.77 per 100,000 individuals was found in the age-standardized incidence rates. Meanwhile, age-standardized prevalence rates ascended from 8.93 to 9.67 per 100,000 individuals, with a remarkable increase in the age-specific prevalence rate for those aged 80 years and above. Survival rates were notably better in younger or treated patients, and in those who underwent Hematopoietic stem cell transplantation. The time of diagnosis did not affect the survival of patients younger than 65 years. However, the most recent survival rates were significantly lower for patients 65 or older, as shown in the unadjusted Cox survival analysis. After adjustments in the analysis, it was found that the overall survival rates of the most recently diagnosed group improved significantly compared with those diagnosed earlier, with a hazard ratio of 0.90 (95% confidence interval, 0.84-0.97). This improvement may potentially be influenced by the enhanced treatment alternatives available for newly diagnosed older patients aged 65 years or older. In conclusion, aging appears to fuel an increase in the number of acute myeloid leukemia cases and mortality. Further studies are warranted to understand the impact of aging on acute myeloid leukemia treatment outcomes and devise efficacious care strategies for older patients.

Asia-Pacific Leukemia Consortium: An innovative and collaborative initiative to improve care of leukemia and related diseases in the Asia-Pacific region

The burden of leukemia and related diseases is rapidly growing in Asia. Currently, there is a paucity of regional collaborative groups/initiatives that focus exclusively on the management of leukemia in the Asia-Pacific (APAC) region. The Asia-Pacific Leukemia Consortium (APLC) was established on the 8 September 2021 to understand the status quo, unmet needs, and ways to improve the management of leukemia and related diseases in the APAC region. The APLC working group set up a group of experts from various countries (Singapore, Malaysia, Thailand, Hong Kong, Japan, South Korea, Taiwan, China, and Australia) to discuss on the status of: (i) clinical trials; (ii) disease registry database; (iii) genetic and tissue repository; (iv) patient advocacy and care; and (v) disease prevention and education in the APAC region. Low levels of awareness about leukemia amongst the public, lack of financial support, and limited access to newly approved therapies were identified as barriers to the implementation of effective leukemia management in low- or mid-income Asian countries. Patients often enroll in clinical trials to gain access to novel/approved therapies. The APLC group aims to address the growing threat of leukemia through a collaborative approach to advance disease prevention, research, clinical trials, and education.

Current and emerging tyrosine kinase inhibitors for the treatment of chronic myeloid leukemia in young adults

INTRODUCTION

Chronic myeloid leukemia (CML) is more common in older adults, but nearly 15-20% of the patients is between 15 and 39 years of age. In this age group, patients may seek clinical care a much later period of the disease and they may have a heavier burden of disease. In addition, young patients with CML may face unique challenges related to their age, such as concerns about health care, fertility, or careers. The current standard of care for CML is the use of tyrosine kinase inhibitors (TKIs), which induce remission in most young patients and can achieve long-term disease control.

AREAS COVERED

This review summarizes age-specific treatment-related conditions, as well as the effectiveness of TKI therapy in this age group. PubMed, Google Scholar, clinicaltrials.gov and other abstract databases were used while preparing this review. The period of 2001-2023 was chosen as the search window.

EXPERT OPINION

Although we do not have sufficient data, young adult population has a special importance for TKI treatment. Clinical features, efficacy of treatments, and specific conditions in this age group should attract more attention of clinicians and more intensive studies should be conducted in the future.

Trends of travel burdens to access cancer care among children with cancer: analysis of a population-based cancer registry data in Aichi, Japan

Centralization of childhood cancer treatment in specialized hospitals is necessary for quality treatment and care, but imposes a time and cost burden for patients and their families. We investigated the 20-year trend in the patients' car travel burden to reach cancer-care hospitals in Aichi Prefecture, Japan. From the Aichi population-based cancer registry data, 1,741 cases diagnosed in 1998-2017 under 15 years of age were extracted and assigned to three treatment groups: invasive treatment (n = 697), radiotherapy (n = 371), or chemotherapy groups (n = 1,462), allowing for duplicate assignment. Their travels to access each treatment hospital were estimated and summarized as the estimated travel times (ETT), estimated travel distances (ETD), and direct distances (DD). The ETTs were compared using the Brunner-Munzel test. The average cases per year for each hospital were plotted. The annual trends during 1998-2017 on ETT, ETD, and DD were investigated using Joinpoint regression models. The ETTs were 0.38-0.45 hours on median for three periods (1998-2005, 2006-2012, and 2013-2017) in three treatment groups and increased by 0.02-0.07 hours from 2006-2012 to 2013-2017, with a statistically significant difference in the radiotherapy group (0.07 hours, P = 0.037). The average cases per year increased for the top hospital in each group, and regression model analyses showed no joinpoint on the annual median trend. In conclusion, the increases in travel times were small and not considered clinically significant, and treatment centralization was observed from 2006-2012 to 2013-2017.

Incidence of second primary cancers among survivors of childhood cancer: A population-based study, Osaka, Japan, 1975-2015

Second primary cancer (SPC) is one of the most life-threatening late effects of childhood cancers. We investigated the incidence and survival outcomes of SPC in childhood cancer patients in Japan. Data were obtained from the population-based Osaka Cancer Registry. Individuals diagnosed with cancer at age 0-14 years during 1975-2014 and survived 2 months or longer were followed through December 2015. The risk of developing SPC was assessed with standardized incidence ratio (SIR), excess absolute risk (EAR, per 100,000 person-years), and cumulative incidence. Multivariable Poisson regression analysis was carried out to assess relative risks of SPC by treatment method. Survival analysis was undertaken using the Kaplan-Meier method. Of 7229 childhood cancer survivors, 101 (1.4%) developed SPC after a median of 11.6 years. Overall SIR was 5.0, which corresponded with 84.3 EAR. The cumulative incidence was 0.9%, 2.1%, and 3.4% at 10, 20, and 30 years, respectively. Among all SPCs, the type that contributed most to the overall burden was cancers in the central nervous system (EAR = 28.0) followed by digestive system (EAR = 15.1), thyroid (EAR = 8.3), and bones and joints (EAR = 7.8); median latency ranged from 2.0 years (lymphomas) to 26.6 years (skin cancers). Patients treated with radiotherapy alone were at a 2.58-fold increased risk of developing SPC compared to those who received neither chemotherapy nor radiotherapy. Among patients who developed SPCs, 5-year and 10-year survival probabilities after SPC diagnosis were 61.7% and 52.0%, respectively. Risk-based long-term follow-up planning is essential to inform survivorship care and help reduce the burden of SPCs in childhood cancer survivors.

Worldwide trends in population-based survival for children, adolescents, and young adults diagnosed with leukaemia, by subtype, during 2000-14 (CONCORD-3): analysis of individual data from 258 cancer registries in 61 countries

BACKGROUND

Leukaemias comprise a heterogenous group of haematological malignancies. In CONCORD-3, we analysed data for children (aged 0-14 years) and adults (aged 15-99 years) diagnosed with a haematological malignancy during 2000-14 in 61 countries. Here, we aimed to examine worldwide trends in survival from leukaemia, by age and morphology, in young patients (aged 0-24 years).

METHODS

We analysed data from 258 population-based cancer registries in 61 countries participating in CONCORD-3 that submitted data on patients diagnosed with leukaemia. We grouped patients by age as children (0-14 years), adolescents (15-19 years), and young adults (20-24 years). We categorised leukaemia subtypes according to the International Classification of Childhood Cancer (ICCC-3), updated with International Classification of Diseases for Oncology, third edition (ICD-O-3) codes. We estimated 5-year net survival by age and morphology, with 95% CIs, using the non-parametric Pohar-Perme estimator. To control for background mortality, we used life tables by country or region, single year of age, single calendar year and sex, and, where possible, by race or ethnicity. All-age survival estimates were standardised to the marginal distribution of young people with leukaemia included in the analysis.

FINDINGS

164 563 young people were included in this analysis: 121 328 (73·7%) children, 22 963 (14·0%) adolescents, and 20 272 (12·3%) young adults. In 2010-14, the most common subtypes were lymphoid leukaemia (28 205 [68·2%] patients) and acute myeloid leukaemia (7863 [19·0%] patients). Age-standardised 5-year net survival in children, adolescents, and young adults for all leukaemias combined during 2010-14 varied widely, ranging from 46% in Mexico to more than 85% in Canada, Cyprus, Belgium, Denmark, Finland, and Australia. Individuals with lymphoid leukaemia had better age-standardised survival (from 43% in Ecuador to ≥80% in parts of Europe, North America, Oceania, and Asia) than those with acute myeloid leukaemia (from 32% in Peru to ≥70% in most high-income countries in Europe, North America, and Oceania). Throughout 2000-14, survival from all leukaemias combined remained consistently higher for children than adolescents and young adults, and minimal improvement was seen for adolescents and young adults in most countries.

INTERPRETATION

This study offers the first worldwide picture of population-based survival from leukaemia in children, adolescents, and young adults. Adolescents and young adults diagnosed with leukaemia continue to have lower survival than children. Trends in survival from leukaemia for adolescents and young adults are important indicators of the quality of cancer management in this age group.

FUNDING

Children with Cancer UK, the Institut National du Cancer, La Ligue Contre le Cancer, Centers for Disease Control and Prevention, Swiss Re, Swiss Cancer Research foundation, Swiss Cancer League, Rossy Family Foundation, US National Cancer Institute, and the American Cancer Society.

Surgical volume threshold to improve 3-year survival in designated cancer care hospitals in 2004-2012 in Japan

In Japan, cancer care hospitals designated by the national government have a surgical volume requirement of 400 annually, which is not necessarily defined based on patient outcomes. This study aimed to estimate surgical volume thresholds that ensure optimal 3‐year survival for three periods. In total, 186 965 patients who had undergone surgery for solid cancers in 66 designated cancer care hospitals in Osaka between 2004 and 2012 were examined using data from a population‐based cancer registry. These hospitals were categorized by the annual surgical volume of each 50 surgeries (eg, 0‐49, 50‐99, and so on). Using multivariable Cox proportional hazard regression, we estimated the adjusted 3‐year survival probability per surgical volume category for 2004‐2006, 2007‐2009, and 2010‐2012. Using the joinpoint regression model that computes inflection points in a linear relationship, we estimated the points at which the trend of the association between surgical volume and survival probability changes, defining them as surgical volume thresholds. The adjusted 3‐year survival ranges were 71.7%‐90.0%, 68.2%‐90.0%, and 79.2%‐90.3% in 2004‐2006, 2007‐2009, and 2010‐2012, respectively. The surgical volume thresholds were identified at 100‐149 in 2004‐2006 and 2007‐2009 and 200‐249 in 2010‐2012. The extents of change in the adjusted 3‐year survival probability per increase of 50 surgical volumes were +4.00%, +6.88%, and +1.79% points until the threshold and +0.41%, +0.30%, and +0.11% points after the threshold in 2004‐2006, 2007‐2009, and 2010‐2012, respectively. The existing surgical volume requirements met our estimated thresholds. Surgical volume thresholds based on the association with patient survival may be used as a reference to validate the surgical volume requirement.

Cancer in adolescents and young adults in Japan: epidemiology and cancer strategy

According to national cancer registry data in Japan, approximately 20,000 adolescents and young adults (AYAs, age 15–39 years) are newly diagnosed with cancer each year. Improvements in treatment and care for AYAs with cancer are included in the Phase Three Basic Plan to Promote Cancer Control Programs in Japan. This article reviews current cancer incidence and survival for AYAs with cancer in Japan using population-based cancer registry data. Mortality data through 2019 from the Vital Statistics of Japan are also described. Encouragingly, the 5-year survival probability for AYA cancers has continued to improve, in parallel with childhood cancers, and the mortality rate has decreased. There has been increasing attention to these vulnerable patients and improved partnerships and collaboration between adult and pediatric oncology; however, obstacles to the care of this population still exist at multiple levels. These obstacles relate to specific areas: research efforts and enrollment in clinical trials on AYA malignancies, AYA-specific psychosocial support such as education, financial support, and oncofertility care, and cancer care systems. It is important for Japanese oncologists, health care providers, and health policy makers to recognize that the AYA population remains vulnerable and still have unmet needs.

Trends in survival of leukemia among children, adolescents, and young adults: A population-based study in Osaka, Japan

This study focused on children as well as adolescents and young adults (AYAs) and aimed to examine trends in survival of leukemia over time using population-based cancer registry data from Osaka, Japan. The study subjects comprised 2254 children (0-14 years) and 2,905 AYAs (15-39 years) who were diagnosed with leukemia during 1975-2011. Leukemia was divided into four types: acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and other leukemias. We analyzed 5-year overall survival probability (5y-OS), using the Kaplan-Meier method and expressed time trends using the joinpoint regression model. For recently diagnosed (2006-2011) patients, a Cox proportional hazards model was applied to determine predictors of 5y-OS, using age group, gender, and treatment hospital as covariates. Over the 37-year period, 5y-OS greatly improved among both children and AYAs, for each leukemia type. Among AYAs, 5y-OS of ALL improved, especially after 2000 (65% in 2006-2011), when the pediatric regimen was introduced but was still lower than that among children (87% in 2006-2011, P < .001). Survival improvement was most remarkable in CML, and its 5y-OS was over 90% among both children and AYAs after the introduction of molecularly targeted therapy with tyrosine kinase inhibitors. Among patients with recently diagnosed AML, the risk of death was significantly higher for patients treated at nondesignated hospitals than those treated at designated cancer care hospitals. The changes in survival improvement coincided with the introduction of treatment regimens or molecularly targeted therapies. Patient centralization might be one option which would improve survival.